Vibrational spectra and conformational isomerism of calixarene building blocks. II. Bis(2-hydroxyphenyl)methane

Abstract

The conformations and vibrational spectra of bis(2-hydroxyphenyl)methane have been analysed within the framework of density functional theory. The calculated force fields (B3LYP/6-31G*) of seven possible energy minima were transformed to internal coordinates, and a set of ten different scaling factors was applied. The scaled quantum mechanical (SQM) method reproduces the experimental IR and Raman spectra with high accuracy. The dependence of the CH₂ stretching vibrations on the conformation and the possibility of its use as a probe for larger systems, e.g., calixarenes or polyphenols, are discussed.